Radiant heating unit



M. H. SHOENBERG.

RADIANT HEATING UNIT.

APPLICATION FILED DEC.27 I919- Patented J an. 11, 1921.

INVENTOR an, #3 I BY J W A TTORNE YS MILTON H. SHOENBERG, OF SAN FRANCI ELECTRIC DEVELOPMENT COMPANY, PORA'IION OF CALIFORNIA.

SCO, CALIFORNIA, ASSIGNOR TO MAJESTIC OF SAN FRANCISCO, CALIFORNIA, A COR- RADIANT HEATING- UNIT.

To all whom it may concern 7 Be it known that I, MILTON H. 'SHOEN- BERG, a citizen of the United States, and a resident of the city and county of San F rancisco, State of California, have invented new and useful Improvements in Radiant Heating Units, of which the following is a specification.

My invention has for its object the attainment of radiant heat in a concentrated beam with the greatest efficiency, simplicity of construction and mechanical advantages and permanency, and these objects I attain by constructing my heating unit of such shape and proportions that the radiant heat energy emanating therefrom is directed principally within the limits of a beam or shaft of radiant heat. The rays are principally directed against a radiant heat reflector surface, and I shape my heating unit in such a way. that the distribution of radiant rays received from the heating unit on the surface of the reflector are distributed therefrom more evenly than from heating units of other forms, so that the said reflector does not become excessively heated as heretofore.

A. further object is the maintenance of the winding on the heat units against distortion of the coils due to conditions of expansion and contraction, and which distortion has heretofore resulted in accumulative looseness of the coils, and their consequent contacting and short circuitin'g,

Otherobjects and advantages will be apparent from the drawings and description which follows.

In utilizing the older forms of heating unit, as for example the well known circular form, the excess of radiant energy received on the center or the proximate portion of the reflector results in a reflecting or returning of the said rays to the heating element itself, and consequently an early burning out or destruction of the resistance wire thereof. This is also accompanied by an interruption of radiant rays, whichwould otherwise contribute to the efficiency of the emanating beam. Such destruction or transformation of a portion of the radiant beam is accompanied by an excess or dangerous heating of the back portion of the reflector.

In Figure 1 I have shown a perspective Specification of Letters Patent.

Application filed December 27, 1919.

Patented Jan. 11, 1921. Serial No. 347,731.

view of my heating element in a preferred form.

In Fig. 2 a special form of heating element isshown in perspective.

At Flg. 3 a cross section through my heating element and itsassociated reflector is shown.

Fig. 4 is the assembled reflector and the heating unit and radiant beam emanating therefrom.

Fig. 5 shows diagrammatically a Well known older form of heating unit and reflector in which the destruction of the heating unit is caused by concentration of radiant rays against the proximate surface of the reflector and their return to the heating unit.

Fig. 6 shows in comparison with Fig. 3 the relative efficiencies of heat emanation in the effective radiant beam.

Fig. 7 shows in perspective a part of my heating unit where a spiral form of winding is employed.

Fig. 8 shows in perspective a part of my heating unit where straight wire winding is employed.

Throughout the figures the same numerals refer to identical parts.

The body or base on which the electrical resistance wire is to be wound is shown by the numeral 1. This may be made of vitreous material, clay, soapstone, or any suitable heat and electric resisting material, and may be molded or cut as desired. WVound upon this base is the electrical resistance 2, of any well known form as shown in Figs. 7 and 8, provided with suitable terminals, or connections 3, 4, to which a suitable supply of electric current is to be furnished for energization. It is to be understood that resistance of this coil is to be suited to the requirements ofthe heater, the determination of its resistance and carrying capacity being well understood.

This heating unit or element I prefer to form in section as a substantially isosceles triangle, the two sides of the said triangle being indicated by the numerals 5, 6 and these are connected across their base 7 forming the front portion of the heating element, by a surface which may advantageously be slightly curved, asand for the purposes set forth below.

The apex. of the said triangle may be curved slightly at 8. Those portions of the heatin element, by which I mean the insulate base 1, on which is wound the wire 2, are fiat and form the sides 5, 6 and are the source of the principal radiant heat emanation, and the principal portion of the said emanating heat is in the general direction of -26 indicate portions of the the lines 9, 10 of Fig. 3, which in turn are received upon the reflecting surface 11, and enia'nate as a radiant beam .12, 13. From the front of the unit or base of the triangle, as 7, and which may beformed as a convex lens or prism, the rays Wlll' diverge depending upon the curvature of the said rism surface 7 as indicated at 14, 15, and prefer to form the said surface? as the base of the triangular. element either flat or very slightly convex,-such that the diverging rays 14,15 will fall within the beam 13, 12- from the reflector 11,-at a predeterm ned d stance.

It will thusbe seen that with this form of radiant-heating unit there may be produced a beam of maximum intensity, there being directly emitted from the triangular base and reflected from the surface of the reflector, practically all of the radiant heat from the heating unit whereas in other forms, as for example the circular form, or that shown in Figs, 5 and 6, practicaily half of the radiant energy from the said un t 18 dissipated in other paths than the straight beam, there being in the latter case, Fig. 6, only those rays emanating between 20 and 21, between 16 and 17 and between 18 and 19 which effectually fall within the straight beam, as indicated by the line 22, and the black spaces shown graphically at 24, 25, heating unit which do not efiiciently contribute to the desired beam 22, whereas it will be seen from Figs. 3 and a that practically the entire surface emanations from the heating unit 1 are concentrated within the beam 13, 13 except a very small percentage at the corners where the wire is, of necessity, bent in circle of minimum radius.

While I have shown and described a triangular form of unit, it is to be observed that the shape of the said triangle and the shape of the reflector receiving-the rays from the sides of the triangle are to be formed and assembled with respect to each other, as generally indicated in Fig. 3. If, however, the reflector be bent farther over the unit, then the triangle whose apex is of aless angle, or an entirely flat heatinunit, as shown at Fig. 2, may be substitute for the triangular shape of Fig. 1. The relationship of the reflector surface andthe emanating surfaces of the heating unit are to be such that rays normally from the sides of the heating unit will impinge upon thev active reflector surface.

,It will be observed that in a triangular heat unit, or one whose cross section in the plane of the windings is polygonal, or presents edges to the winding as here set forth, that the wire of the winding is bent around the corner, or edge, or where the faces of the polygon meet, providing in effect a locking of each of the wire coils which prevents creeping of the wire under conditions of extension and contraction and thus prevents an unequal looseness of the' coils throughout parts of the heat unit which as in earlier forms had the disadvantage or" allowing adjacent coils when so loosenedto contact and short circuit. I

It is also to be understood that in addition to various forms of material which may be used in constructing the heating unit base and the resistance w re thereon, there may be employed holding means for the wire, or the Wire may be embedded in grooves or otherwise mechanically supported, or it may be in the form of a spiral, and the spiral wound on the base, as occasion or the taste of the designer demands, but all within the spirit of my invention.

My invention is particularly adapted to electric heat radiators in which a resistance wire is employed and energized by an elecdirecting the said emanation in a desired direction.

I claim- 1. A radiant heating unit having a cross section in the form of an isosceles triangle, provided with electrical resistance constructed and adapted to emanate heat upon the energization of said resistance.

2. A radiant heating unit having a cross section in the form of an isosceies triangle, provided with electrical resistance constructed and adapted to emanate heat upon the energization of said resistance in combination with a concave reflector, the said unit having the plane midway between its triangular sides passing through the axis oi the concave surface of the reflector.

3. A radiant heating unit having a cross section in the form of an isosceles triangle,

provided with electrical resistance constructed and adapted to emanate heat upon the energization of said resistance in combination with a concave reflector, the said unit having the plane midway between its.

triangular sides passing through the axis of the concave surface of the reflector, and EIlOlOSlIlg also the focus of said concave sur-- ace.

4. A radiant heating unit of triangular section in. combination with a concave reradiant rays normal to flector, and disposed about the focus of said reflector, said unit mounted with its apex adjacent the reflector, and the sides of said unit presenting surfaces normal to a radiant beam, which falling upon the reflector is reflected parallel to the axis of the concavity of the reflector.

5. A radiant heating unit in combination with a concave reflector, and disposed about the focus of said reflector, said unit mounted with its apex adjacent the reflector, and the sides of said unit presenting surfaces normal to a radiant beam, which falling upon the reflector is reflected parallel to the axis of the concavity of the reflector.

6. A radiant heating unit having a cross section in the form of an isosceles triangle, provided with electrical resistance constructed and adapted to emanate heat upon the energization of said resistance, the base of the triangular section curved to project said surface and falling within the reflected beam emanating from the sides of said unit. 1 r

'7. A radiant heating unit having a cross section in the form of an isosceles triangle, provided with electrical resistance constructed and adapted to emanate heat upon the energization of said resistance, the base of the triangular section curved to project -radiant rays normal to said surface and fallmg within the reflected beam from the sides of emanating said unit,

8. A radiant heating unit having a cross section in the form of an isosceles triangle, provided with electrical resistance constructed and adapted to emanate heat upon the energization of said resistance in combination with a concave reflector, the said unit having the plane midway between its triangular sides passing through the axis of the concave surface of the reflector, and inclosing also the focus of said concave sur' face, the base of the triangular section curved to project radiant rays normal to said surface and falling withinthe reflected beam emanating from the sides of said unit.

.9. A radiant heating unit in combination with a concave reflector, and disposed about the focus of said reflector, said unit mounted with its apex adjacent the reflector, and the sides of said unit presenting surfaces normal to a radiant beam, which falling upon the reflector is reflected parallel to the axis of the concavity of the reflector, the base of the triangular section curved to project radiant rays normal to said surface and falling within the reflected beam emanating from. the sides of said unit.

10. In a radiant heating unit, a winding of electrical resistance adapted to electrical energization to produce heat, said Winding mounted upon an insulating and heat resisting base of prism form and hollow throughout its length forming a shell of substantially equal thickness throughout.

MILTON H. SHOENBERG. 

